An airplane on a treadmill: will it take off?

[NotAllThere]

Is it a powered treadmill or unpowered?

If unpowered, then with the jets off, nothing happens. As the jets fire up, the plane will move forward.

If powered and with direction of movement taking the plane backwards with the jets off, the plane will move backward, dragged along by the friction. As the jets fire up, the rate of motion will be slowed, and then reversed.

If powered and with direction of movement taking the plane forwards with the jets off, the plane will move forward, dragged along by the friction. If moved by the treadmill sufficiently quickly it will take off. As the jets fire up, the point of take off is more quickly reached.

In all cases, the plane will take off.

[gingerjedi]

If you assume the wheels have no rpm limit and they have little friction then they are inconsequential to how fast the treadmill runs, the engines just need to overcome the friction of the wheels.

It will take off, I can't believe anyone on here would think otherwise.

[Moscow Mule]

Obviously the treadmill must be able to run at speeds sufficient to keep it at zero mph

You are assuming that the treadmill can exert sufficient friction on the wheels to force the plane backwards with the engines switched off.

[Menelaus]

Serious Mode = ON

This is what I love about CUK. Whereas some other forums would be based around how many pints people drank last night, who was shagging who in meaningless soap x etc - here we get into over physics problems.

Serious Mode = OFF

HTH

[gingerjedi]

If you tethered the plane from the front and switched the treadmill on it would take little force to hold the plane in its original position, again assuming the wheels are free running and have little friction.

The engine would need to generate normal take off thrust + a small amount to overcome the additional wheel friction.

Simples.

[Pondlife]

Yes it will take off.

[BoredBloke]

No it won't because it would crash into that barrier thing with all the buttons on it

[Churchill]

No it won't because it would crash into that barrier thing with all the buttons on it

Movement in relation to the ground is not what lifts an aeroplane into the air, it's movement in relation to the air flowing over and under its wings.

[BoredBloke]

At some point it would crash into that barrier where you put your drinks!

[scooterscot]

I was delivering a van full of Budgerigars to the pet shop the other day and I thought would the van be any lighter if they were in flight during transit???